Extend YamlErbParser to understand __FILE__ when interpolating ERB.

2 files changed, 33 insertions, 1 deletions

diff --git a/lib/hashie/extensions/parsers/yaml_erb_parser.rb b/lib/hashie/extensions/parsers/yaml_erb_parser.rb
index 7b6a5c4..d0b1cb0 100644
--- a/lib/hashie/extensions/parsers/yaml_erb_parser.rb
+++ b/lib/hashie/extensions/parsers/yaml_erb_parser.rb
@@ -6,10 +6,13 @@ module Hashie
       class YamlErbParser
         def initialize(file_path)
           @content = File.read(file_path)
+          @file_path = file_path
         end
 
         def perform
-          YAML.load ERB.new(@content).result
+          template = ERB.new(@content)
+          template.filename = @file_path
+          YAML.load template.result
         end
 
         def self.perform(file_path)
diff --git a/spec/hashie/parsers/yaml_erb_parser_spec.rb b/spec/hashie/parsers/yaml_erb_parser_spec.rb
new file mode 100644
index 0000000..15482d0
--- /dev/null
+++ b/spec/hashie/parsers/yaml_erb_parser_spec.rb
@@ -0,0 +1,29 @@
+require 'spec_helper'
+
+describe Hashie::Extensions::Parsers::YamlErbParser do
+  describe '.perform' do
+    let(:config) do
+      <<-EOF
+---
+foo: verbatim
+bar: <%= "erb" %>
+baz: "<%= __FILE__ %>"
+      EOF
+    end
+    let(:path) { 'template.yml' }
+
+    subject { described_class.new(path).perform }
+
+    before do
+      expect(File).to receive(:read).with(path).and_return(config)
+    end
+
+    it { is_expected.to be_a(Hash) }
+
+    it 'parses YAML after interpolating ERB' do
+      expect(subject['foo']).to eq 'verbatim'
+      expect(subject['bar']).to eq 'erb'
+      expect(subject['baz']).to eq path
+    end
+  end
+end